Sina, a prominent Chinese media company that runs a Twitter-like microblogging service (Weibo), has announced new rules for its users that threaten to end the relatively open, anonymous discussion of issues through their service.

In the latest move towards Internet censorship and the crackdown on free speech, Sina Corp, a major online media provider for China and Chinese expatriate communities, has issued a “code of conduct” for Weibo, its microblogging service similar to Twitter. First announced earlier this month, the code contains many rules, some of which include forbidding users from posting information that is “against the principles of the constitution,” would “harm national unity, disclose state secrets,” or is deemed to be “false information,” which sounds suspiciously like a catch-all for “anything we don’t want the general populace to see.”

Users have called out the restrictions, saying that they’re aimed at silencing the anonymous and often vehement, scathing voicing of complaints against the government in a country where the Internet offers one of a small few places with the opportunity of the open discussion of issues.

Sina also introduced a point-based system, wherein each user starts with 80 points and loses points for every violation, with a zero score causing a cancellation of the account. The only way to gain points is by a user validating their real identity, making the targeting of dissenters even easier.

This comes as the latest in a series of actions designed to rein in discussion on Weibo as China prepares for its 18th Congress, which will result in a leadership handover, something that happens only once every decade. A prominent member of the Weibo community commented that it gives them “a firmer basis for expanding a ban on whatever is considered sensitive news,” the definition of which has continuously expanded. “Of course, nowadays, they’re worried because of all the scandal and rumors before the 18th Congress.” Internet users have skirted restrictions in the past on Weibo by using code words to discuss issues, as Sina employs technicians whose sole job is to scrub the site of sensitive posts.

Beijing demanded last December that microblogging operations such as Weibo ensure that users of their services are registered with their real names. Sina has said that this will be hard, given that their service has roughly 300 million users. The company also plans on making money from Weibo this quarter in order to try and recoup the massive investment they’ve made in the service.